On Fri, 19 Nov 2021 10:35:26 +0100 (CET)
Richard Biener via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> On Fri, 19 Nov 2021, Alexandre Oliva wrote:
>
> > On Nov 18, 2021, Richard Biener <rguent...@suse.de> wrote:
> >
> > > IMHO a more reasonable thing to do would be to not treat
> > > -o /dev/null as a source for -dumpdir and friends. Alex?
> >
> > +1
> >
> > I think we already have some special-casing for /dev/null somewhere.
>
> Grepping finds me the following in system.h which is already checked
> for in gcc.c in a few places indeed.
>
> /* Provide a default for the HOST_BIT_BUCKET.
> This suffices for POSIX-like hosts. */
>
> #ifndef HOST_BIT_BUCKET
> #define HOST_BIT_BUCKET "/dev/null"
> #endif
>
>
> > > You did the last re-org, where'd we put such special casing?
> >
> > I think we're missing something like this, to avoid messing with dumpdir
> > with -o /dev/null. We already use the same function when computing
> > outbase just below this.
>
> Ah yeah, not_actual_file_p should do the trick indeed. Giuliano, can
> you update the patch like below? I think we should still adjust
> documentation as you did.
But that wouldn't cater for the general problem that the dumpdir is not
writable, no? Why not just simply check access W_OK of the dumpdir?
Otherwise a dumpdir /dev/full or anyother such path will cause the same
thing i guess.
thanks,
>
> > diff --git a/gcc/gcc.c b/gcc/gcc.c
> > index 506c2acc282d6..a986728fb91d6 100644
> > --- a/gcc/gcc.c
> > +++ b/gcc/gcc.c
> > @@ -5098,7 +5098,8 @@ process_command (unsigned int decoded_options_count,
> >
> > bool explicit_dumpdir = dumpdir;
> >
> > - if (!save_temps_overrides_dumpdir && explicit_dumpdir)
> > + if ((!save_temps_overrides_dumpdir && explicit_dumpdir)
> > + || (output_file != NULL && not_actual_file_p (output_file)))
> > {
> > /* Do nothing. */
> > }
> >
